Search narrows for Air France Flight 447 black boxes

Based on a new analysis of sonar "pings," French investigators are focusing attention on a smaller area of the Atlantic to continue the hunt for the black boxes that could reveal why the Air France Flight 447 crashed last June.

French general Christian Baptiste speaks during a news conference about the location of Air France black boxes from the 2009 crash in Paris on Thursday. The location of black box recorders, from Air France Flight AF447 crash between Rio de Janeiro and Paris that killed 228 people, has been sharply narrowed down in the Atlantic Ocean.

Benoit Tessier/Reuters

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French investigators have narrowed the search area in the hunt for the flight data recorders from the tragic Air France Flight 447 crash, boosting the possibility that relatives of victims and aviation experts will someday know why the Brazil-to-France flight crashed into the Atlantic last June.

But the prospect of locating the black boxes, believed now to be somewhere in an area approximately the size of Paris, in terrain that resembles the Andes, remains a formidable task. “It’s smaller than the southern Atlantic ocean,” says Robert Mann, president of R.W. Mann & Company, aviation consultants in Port Washington, N.Y. “But it’s one particular haystack among a field of haystacks.”

The Air France 447 flight, which took off from Rio De Janiero en route to Paris, crashed June 1, killing all 228 people on board. Until the black boxes are recovered, there is little hope that the true cause of the disaster will ever be known. According to a preliminary report, seen by the French newspaper Liberation on April 25, nine pitot tubes were considered "degraded" by experts who examined them. Bad weather and faulty pitot tubes (the airspeed sensors) have been oft-cited theories as to the disappearance of the flight.

The new, smaller search area is based on a new computer analysis of the "pings" picked up by the sonar of a French submarine during the initial search effort. “It is probably the signal [of the flight data recorders],” said General Christian Baptiste, deputy spokesman at the French Defense Ministry.

Investigators can now reduce their search from the 700-square miles that had been the target zone. The French agency investigating the disaster, BEA, said it will begin searches in the new zone Friday.

The finding could help investigators pinpoint major pieces of wreckage, and, in the best scenario, the black boxes themselves. Air France called the breakthrough “excellent news.”

The news comes nearly a year after the disaster. Recorders have been located long after crashes, like ones located from an Air India crash or South African Airways flight that burned in air, Mr. Mann says. But in this case, huge barriers remain.

“The unfortunate part is that had this been realized concurrent with when it was obtained it would have been a lot more useful. The ‘pingers’ still would have been active,” says Mann. Given the lapse of time, searchers will have to rely on side-scan sonar and visual identification. The boxes could lie anywhere between a half mile and 2.5 miles under water. They are also essentially the size of the shoebox. To put the task into perspective, Mann says that finding the undersea wreckage of the Titanic and battleships from World War II were a challenge.

“I presume it’s going to be a pretty difficult task to find a shoebox. From a sonar perspective, it will look like a very noisy environment,” Mann says.

Luc Chatel, a French government spokesman, urged caution too: “We must see if there is a possibility to recover the black boxes, what depth they are located in,” he said. “It would obviously be very good news for everyone, first for the families of the victims of the flight, and then for all of us, because it has been one year that we have been waiting with impatience to find out what really happened on the Rio-Paris flight.”